Supernova 1987A and the Nibu Gemani

[BobGreenwade]

I saw this article this morning, and it's been bothering me ever since. Only just a few minutes ago did I realize why: in Galactic Champions (p. 113), the Nibu Gemani are said to be from "one of the far-off Magellanic Cloud galaxies." Given that Supernova 1987A happened in the Greater Magellanic Cloud... that could have some interesting implications for the future history of the Galactic Federation.

For that matter, one could insert implications in just about any starfaring universe.

[cptpatriot]

I don't have the book here, but do these fungoids or fungi in general thrive in radiated environments?

[BobGreenwade]

Well, the Typical Nibu Gemani character sheet does include Life Support with Safe Environment: High Radiation. I don't know about fungi in general.

[Lord Liaden]

Um, this supernova is 168,000 light-years from us. The explosion happened that many years ago. Any effect it might have had on any living creatures in the Large Magellanic Cloud would have dissipated a very long time ago.

Could it have been responsible for the creation of the Nibu Gemani? Or the impetus for their initial migration? Certainly possible. But frankly, I'm not seeing how that in itself significantly changes conditions in the Galactic Federation era.

Now, if a similar supernova occurred much closer to us, that could have a devastating impact. Is that the point you were trying to make?

[BobGreenwade]

Um, this supernova is 168,000 light-years from us. The explosion happened that many years ago. Any effect it might have had on any living creatures in the Large Magellanic Cloud would have dissipated a very long time ago.

Could it have been responsible for the creation of the Nibu Gemani? Or the impetus for their initial migration? Certainly possible. But frankly, I'm not seeing how that in itself significantly changes conditions in the Galactic Federation era.

Now, if a similar supernova occurred much closer to us, that could have a devastating impact. Is that the point you were trying to make?

No, the scenarios you mentioned are exactly what I had in mind -- either their creation, or their migration.

And if that's so... then what might happen if a bunch of them are in the vicinity of a supernova in the Milky Way?

[Cancer]

The Crab supernova was observed here on Earth in 1054 AD; it's about 6500 light-years from us. The nebula is still expanding at 1500 km/s.

[Drhoz]

Bah, 1987A, schm-1987A. That's nothing. I wouldn't want to be around the Magellanic clouds when Eta Carinae goes up - and it possibly already has. It's already four million times as luminous as the Sun.

Heck, if it's pointed right even Earth won't be safe

"A supernova or hypernova produced by Eta Carinae would probably eject a gamma ray burst (GRB) out on both polar areas of its rotational axis. Calculations show that the deposited energy of such a GRB striking the Earth's atmosphere would be equivalent to one kiloton of TNT per square kilometer over the entire hemisphere facing the star with ionizing radiation depositing ten times the lethal whole body dose to the surface.[23] "

[Cancer]

"A supernova or hypernova produced by Eta Carinae would probably eject a gamma ray burst (GRB) out on both polar areas of its rotational axis. Calculations show that the deposited energy of such a GRB striking the Earth's atmosphere would be equivalent to one kiloton of TNT per square kilometer over the entire hemisphere facing the star with ionizing radiation depositing ten times the lethal whole body dose to the surface.[23] "

Yeah, that's about the number I got (though in different units) in this thread about gamma-ray bursters.

Eta Car, though, even if it does explode -- which people go back and forth about, because it is losing mass so copiously if unsteadily (though a lot of the argument antedates the Chandra x-ray data, and I need to read more before I can tell what that means) -- probably isn't pointed at us. If you look at the eta Car nebula it looks more cylindrically symmetric than circularly symmetric, and the cylinder axis, as presented in the image on that linked page, looks like it's about at 8 o'clock-2 o'clock, with the 8 o'clock end tipped up out of the plane of the image by 30 degrees or so: it doesn't look to be pointed right at us. It isn't guaranteed, but the interior should be rotating in the same direction as the outer envelope.

[Drhoz]

Yeah, that's about the number I got (though in different units) in this thread about gamma-ray bursters.

Eta Car, though, even if it does explode -- which people go back and forth about, because it is losing mass so copiously if unsteadily (though a lot of the argument antedates the Chandra x-ray data, and I need to read more before I can tell what that means) -- probably isn't pointed at us. If you look at the eta Car nebula it looks more cylindrically symmetric than circularly symmetric, and the cylinder axis, as presented in the image on that linked page, looks like it's about at 8 o'clock-2 o'clock, with the 8 o'clock end tipped up out of the plane of the image by 30 degrees or so: it doesn't look to be pointed right at us. It isn't guaranteed, but the interior should be rotating in the same direction as the outer envelope.

Oh, I know that. Still, great SF scenario And it's still going to make life interesting for anybody in the region when it does go up

[Cancer]

If the GRB blast did happen in eta Car, the beam would blast a plasma channel through the nebula that would persist for a while and be visible to various instruments from orbit, I think. And you could work out what target was hit by the burst.

Then if you have reason to think that gamma-ray bursts were triggered things, you are left with the question, who triggered the burst to zap that target, and why? And do you get involved, if you have a choice?